Dude, you're The Flash!
I've had it tell me that before, too. It sucks. If their lawyers are too queasy about using a phone and driving they should just make a pop-up that's says you shouldn't use the app while driving and hit OK to dismiss the warning.
A buddy was driving me back to my car once and since it was hot I wanted to use my phone to start it and let the AC run. Unfortunately the app makes no distinction between riding as a passenger and driving. I had to wait for him to catch a red light before I could do it.
At the very least they should set the movement threshold a little higher so walking doesn't register.